Conventionally, flat panel displays are manufactured based on glass substrate technology. However, due to the limitations of the mechanical characteristics of the present glass substrate technology, future public display application requirements will not be fulfilled. As such, new generations of display devices with flexible substrates have been developed for satisfying requirements, such as lightness and thinness of devices, devices being able to be hung up, and displaying texts and dynamic images according to different usage situations. In addition, smart portable devices of new generations require more functions, such as convenient portability and sturdiness of the devices. Accordingly, the development trend of displays also includes satisfying requirements of lightness and thinness of devices, rigidness and crashworthiness, and big panel sizes with good portability.
Among the manufacturing processes of a flexible display device, the packaging process is a very critical one, because light emitting materials and metallic electrodes are very sensitive to water and oxygen in the environment. When the sealing is poor, the luminance of devices may be reduced, the driving voltage may be raised, and black dots and short circuits may occur. Therefore, the packaging process requires a very strict standard for preventing water and oxygen from penetrating into the device. At present, in the packaging process of a flexible display device, the package cover and the lower substrate are adhered by pressure sensitive adhesive or twin adhesive laminators. However, the water-oxygen resistance abilities of pressure sensitive adhesive and twin adhesive laminators are poor, causing lifetime of displays to be shortened. In contrast, epoxy resin, which is provided with great electrical properties, adhesive properties, and weatherabilities, has been extensively used in electronic devices, such as electrical insulated components, laminated plates, and electronic semiconductor packages. Still, the adhesive ability of epoxy resin to flexible substrates can not be improved by adding silicon-containing coupling agent. Therefore, it is necessary to develop suitable packaging materials or protective materials for the surfaces of flexible substrates.